All of the contents disclosed in Japanese Patent Application No. HI 1-62965 (filed on Mar. 10, 1999), including specification, claims, drawings and abstract, are incorporated into the present application by cross-reference to all these disclosed contents.
1. Field of the Invention
The present invention relates to an ink supply control device for printing machines and a method for controlling ink supply.
2. Description of the Prior Art
A conceptual view of an ink supply device for printing machines is illustrated in FIG. 9. FIG. 9 is a side view of an inking unit 50, a plate cylinder 6, a dampening device 29 and so on included in a printing machine. An ink fountain 2 includes both an ink fountain roller 4 and a blade 3, and the blade 3 comprises a plurality of ink fountain keys divided in the direction of a roller shaft 4J of the ink fountain roller 4. The ink 10 stored in the ink fountain 2 is fed on the external surface of the ink fountain roller 4 through gaps formed between the keys and the roller 4.
An ink ductor roller 5 situated at a position between an ink roller 31 of an ink roller group 30 and the ink fountain roller 4, is reciprocally moved in both directions of arrows 91 and 92, so that the ink 10 fed on the external surface of the ink fountain roller 4 is transferred onto the ink roller 31. The ink 10 thus transferred is finally supplied to a printing plate 7 disposed on a plate cylinder 6 as a result of sequentially distributing the ink 10 onto each of ink rollers in the group 30. The dampening device 29 is a device for supplying dampening solution to the printing plate 7.
In this way, both the ink and the dampening solution are supplied to the printing plate 7. Image(s) on the printing plate 7 is transferred on a printing paper through a rubber blanket cylinder 8 as a result of using repulsion occurring between the ink and the dampening solution both supplied to the plate 7.
A conventional method of controlling ink film thickness is disclosed in Japanese laid-open publication No. Hei 10-16193. In the control method, ink films in the minimum thickness required for carrying out printing work are formed on the ink rollers as a result of feeding the ink 10 from the keys uniformly opened when the printing work is carried out under a condition of not distributing the ink on the group 30.
Thereafter, a certain volume of the ink 10 corresponding to the image(s) on the printing plate is further distributed on the ink films in an axial direction by setting both an opening degree of each key and rotating amount of the ink fountain roller at values corresponding to the image(s) on the printing plate.
The conventional control method, however, has the following problems to be solved. These are various kinds of printing papers such as coated papers, mat coated papers and non-coated papers.
With coated papers, the printing work can be carried out with a less volume of ink because the coated printing papers have a good ink film transferability. With non-coated papers, on the contrary, a larger volume of ink needs to be supplied for carrying out the printing work because the non-coated printing papers have a poor ink film transferability. Further, mat coated papers have an intermediate ink film transferability between the coated papers and the non-coated papers. In general, non-coated papers are frequently used as printing papers because of a price lower than that of coated papers.
Although a different volume of ink is required depending upon the kind of papers, an appropriate control of the ink supply with certainty corresponding to the kind of papers can not be performed in the ink supply of the prior art printing machine.
In other words, the operator of the machine has to adjust the ink volume in accordance with the printing papers to be used at every time when the kind of printing papers is changed to another. That is, the operator must reset the opening degree of the keys, the rotating amount of the ink fountain roller, and the number of the reciprocal movement of the ink ductor roller 5 at every change of printing paper. To make the matter worse, the operator must select optimum values from the stored values based on his/her experience.
It takes a long time to carry out control of the ink supply corresponding to the kind of papers in the prior art ink supply. An appropriate control of the ink supply with certainty can not be expected all the time if the control is performed based on the operator""s experience.
It is an object of the present invention to provide an ink supply control device and a method therefore capable of carrying out appropriate controls with certainty in accordance with the kind of the printing paper.
In accordance with characteristics of the present invention, there is provided an ink supply control device for printing machines including an ink supply portion for supplying ink to a printing plate, the device further comprising:
a paper coefficient storing portion for storing a plurality of paper coefficient uniquely determined corresponding to kinds of printing papers; and
an input portion for inputting a kind of the printing paper to be printed,
wherein a paper coefficient corresponding to the kind of the printing paper inputted through the input portion is selected from the paper coefficient stored in the paper coefficient storing portion,
and wherein the ink supply portion controls supply of an ink volume to the printing plate in accordance with the selected coefficient.
While the novel features of the invention are set forth in a general fashion, both as to organization and content. Other objects and features of the present invention will be more apparent to those skilled in the art on consideration of the accompanying drawings and following specification wherein are disclosed several exemplary embodiments of the invention with the understanding that such variations, modifications and elimination of parts may be made therein as fall within the scope of the appended claims without departing from the spirit of the invention.